Spin-stabilized projectiles are fired from rifled or smoothbore barrels which make the bullet rotate quickly, either via spiral-shaped rifling or else a corresponding design of aerodynamically effective surfaces, which stabilizes the flight path by spinning forces. When fired from rifled barrels, depending on the spiral angle of the rifling, a few thousand rotations per second are achieved. After leaving the muzzle, the projectile is slowed down along its path by drag forces which depend on the shape of said projectile and on its speed.                In the front nose portion of the projectile, it is mainly form drag forces comprising dynamic pressure and wave impedance that are active.        In the central, usually cylindrically shaped, portion of the projectile, it is mainly frictional forces from the turbulent boundary layer that are active.        In the rear tail portion, it is mainly forces from the pressure drop in the so-called stagnation area of the blunt base of the projectile that are active.        
In order to achieve a high range, the bullet must have a high initial speed, preferably a supersonic speed, and the drag forces must be kept as low as possible, so that the energy loss of the projectile along the trajectory is minimized. For this purpose, the nose of the projectile has a drag-optimized shape, preferably that of an ogive, and the tail is slightly tapered, this being known as the boat tail, so that the effective cross section of the pressure drop at the base of the projectile is reduced. A further increase in the base pressure can be achieved by an additional outflow of gas at the projectile base, known as base bleed, as a result of which the range can be increased significantly.
The disadvantage with all projectiles is the loss of kinetic energy due to drag forces, which reduces the range and target impact of the bullet. In the case of base bleed bullets, the additional expenditure on propellant gas which has to be carried by the projectile and ejected along the trajectory is just as much a problem as the possibly irregular burn-off of corresponding gas-generating burn-off sets.